Anybody having trouble with TS Preamp tubes??

[Klark]

Going by everyone's rave reviews of the TS and JP tubes, I ordered four TS's for my V2 positions, and two JP's for a couple V1 positions. I had two TS's dead right off the bat.

After a good while of tweaking, I do not like them. The gain structure and noise levels changed considerably. You have to jack up gain controls, tone controls, and your master way up to get back where you started from. That's not much of a problem, except when you consider component values that Egnater chose. Even the sweep of the knobs seems to change, probably because there's a resistance value of the pot that's not receiving what's it's designed to receive. They were designed and tweaked using the stock(Chinese?) tubes and that's what will work the best. I know some of you guys swear by changing these tubes, but it's not for me, even after giving it at least a half day of tweaking.

If anyone is looking for two brand-new TS's and two brand-new JP's, let me know, I'll sell 'em cheap.

 

[Buckeyedog]

Dude, almost sounds like your other TS are bad too. There should not be a significant difference in the gain/volume from the stock tubes. If you have to crank them way up just to get where you were with the stock tubes, then your replacements are bad too. At least that's been my experience after years at this stuff!! Try replacing only one at a time in the different slots. Keep a stock tube in V2 and put a 5751 in V1 of a lower gain module. Then try the same with your TS tubes. You can narrow it down to which one's are problems.

 

[3 Mile Stone]

I will also hand it to Bruce & Co. for going with Groove Tubes to supply there Tour Master series. When you think about it, it makes some sense. All the current tubes, no matter what brand they silk screen on the glass are all made in one of ever smaller number of factories. It is not the brand that matters it's the fact that someone with knowledge, experience and a system of grading and sorting out the good from the garbage does their thing. Groove Tubes is the one to go with for that reason.

 

[guitarslinger]

I will also hand it to Bruce & Co. for going with Groove Tubes to supply there Tour Master series. When you think about it, it makes some sense. All the current tubes, no matter what brand they silk screen on the glass are all made in one of ever smaller number of factories. It is not the brand that matters it's the fact that someone with knowledge, experience and a system of grading and sorting out the good from the garbage does their thing. Groove Tubes is the one to go with for that reason.

I thought they already stopped using groove tubes b/c it wasn't worth the cost???

 

[aeroic]

I will also hand it to Bruce & Co. for going with Groove Tubes to supply there Tour Master series. When you think about it, it makes some sense. All the current tubes, no matter what brand they silk screen on the glass are all made in one of ever smaller number of factories. It is not the brand that matters it's the fact that someone with knowledge, experience and a system of grading and sorting out the good from the garbage does their thing. Groove Tubes is the one to go with for that reason.

I thought they already stopped using groove tubes b/c it wasn't worth the cost???

I'm pretty sure you're right Gene. I think Guitar Center pushed them into the groove tube route, but after a bunch of DOA tubes, they're moving to Sovtek. At least that's what my memory tells me....it tends to lie from time to time!

Eric

 

[3 Mile Stone]

That would be me not keeping up. Wow, so it's tough out there huh? I guess it pays to do regular business with someone reputable so that it least you have recourse if they tank on you.

 

[bruce egnater]

Don't misunderstand. I'm not defending the "tone" of the 12AX7WA, though they do sound fine. Of course there are lots of different and possibly better sounding tubes so, by all means, try them. I was just pointing out the fragility and unpredictable quality of tubes in general. We've had good reliability with Sovtek which is why we use them. The Groovetubes testing process did not really live up to our expectations. In their defense, many of the preamp tubes that we had so much trouble with did pass their inspection and failed later. This was not Groovetube's fault, really. We have now implemented our own in house testings procedures that will allow us to keep tighter quality control. We also have stopped using the brand that we had the almost 20% failure rate with. Yes, I said 20%!!!!!!! FYI, we paid alot of money for those "so called" superior tubes. Went back to Sovtek 12AX7WA and guess what? Less than 1% bad instead of 20%.

 

[muudrock]

Don't misunderstand. I'm not defending the "tone" of the 12AX7WA, though they do sound fine. Of course there are lots of different and possibly better sounding tubes so, by all means, try them. I was just pointing out the fragility and unpredictable quality of tubes in general. We've had good reliability with Sovtek which is why we use them. The Groovetubes testing process did not really live up to our expectations. In their defense, many of the preamp tubes that we had so much trouble with did pass their inspection and failed later. This was not Groovetube's fault, really. We have now implemented our own in house testings procedures that will allow us to keep tighter quality control. We also have stopped using the brand that we had the almost 20% failure rate with. Yes, I said 20%!!!!!!! FYI, we paid alot of money for those "so called" superior tubes. Went back to Sovtek 12AX7WA and guess what? Less than 1% bad instead of 20%.

I personally have no trouble with the Sovteks. Great all around tube. I find it very interesting that you had that high of a failure rate on tubes. I rarely run into bad preamp tubes, at least at the level I have recently. I've definitely run across bad EL34s but I've had great luck with GT E34Ls. I guess it's the price we pay to play tube based amps.